From 7e78636e8e7c5b50d6d63ec55edc7be9578d2b80 Mon Sep 17 00:00:00 2001 From: Christian Semmler Date: Sun, 7 Dec 2025 06:54:02 +0100 Subject: [PATCH] Handle SharedArrayBuffer for PNG data The Emscripten support for setting window icons introduced in #14490 does not work when using pthreads. Using `SetWindowIcon` will cause the program to crash. The reason for that is that the `Blob` constructor does not accept shared memory (`SharedArrayBuffer`). We need to create a local copy of the icon data if necessary. --- src/video/emscripten/SDL_emscriptenvideo.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/video/emscripten/SDL_emscriptenvideo.c b/src/video/emscripten/SDL_emscriptenvideo.c index e2b6a56854..e7fd9d42fa 100644 --- a/src/video/emscripten/SDL_emscriptenvideo.c +++ b/src/video/emscripten/SDL_emscriptenvideo.c @@ -812,6 +812,11 @@ static bool Emscripten_SetWindowIcon(SDL_VideoDevice *_this, SDL_Window *window, // Pass PNG data to JavaScript MAIN_THREAD_EM_ASM({ var pngData = HEAPU8.subarray($0, $0 + $1); + if (pngData.buffer instanceof SharedArrayBuffer) { + // explicitly create a copy + pngData = new Uint8Array(pngData); + } + var blob = new Blob([pngData], {type: 'image/png'}); var url = URL.createObjectURL(blob);